1. Field of Invention
The invention relates to processes for producing an underground zero of fragmented and pervious material which may be used as a storage area, as a passage or aquifier, for treatment of materials, for ore body leaching or recovering of carbonaceous materials from subterranean deposits, etc. The present process is considered to be a general one of breaking and rendering permeable a mass of rock underneath an impermeable mass of rock and may be used in the production of in situ retorts in oil shale deposits, extracting oil from tar sands, in situ gasification of coal, leacing copper out of a copper deposit or uranium out of a uranium deposit. Essentially, the present process is directed to the selective breaking of a mass of rock in the ground without breaking all of the rock up to the surface.
2. Description of Prior Art
As is well known, large amounts of hydrocarbon oil are contained in subterranean oil shale deposits, and the economic recovery of such oil, and/or hydrocarbon gases, has been a long-sought-after objective. Access to the oil shale may be obtained by removing the overburden by strip mining procedure. However, such procedure is both costly and deleterious to the terrain. Efforts have accordingly been made to extract the oil and valuable hydrocarbon gases by the production of subterranean retorts in the oil shale deposit with minimum disturbance of the land surface. An example of such procedure is disclosed in my U.S. Pat. No. 4,037,657. Another technique for the production of the subterranean retort is the application Ser. No. 895,243 of Daniel P. Zerga, filed Apr. 10, 1978.